崩积层之分类与工程特性研究   总被引：1，自引：0，他引：1  

董家钧  杨贤德 《水土保持研究》2001,8(1):37-41,46

崩积层堆积之坡地常被列为不可开发区。然因崩积层不易取样以及取样后之代表性不足，造成崩积层工程特性研究之困难。搜集整理多件台湾重要之山崩案例，并按不同山崩机抽进行分类统计，以对于各类型山崩所产生之崩积层产状作一探讨。最后以不同型态之崩积层开发利用实例，对于不同崩塌机制所产生之崩积层之工程特性调查作一探讨。  相似文献   

牧草压缩工程中几个主要问题分析     

杨明韶  王春光 《农业工程学报》1997,13(5):134-138

对牧草、秸秆压缩工程中生产率提高的理论依据、压缩产品形态保持机理以及压缩过程的模拟分析三个主要问题，进行了论证分析。  相似文献   

Effect of starter fertilizer in seed-row on emergence,biomass and nutrient uptake by six pulse crops grown under controlled environment conditions     

Wasanthika Harshini Galpottage Dona  Jeff J. Schoenau  Tom King 《Journal of plant nutrition》2020,43(6):879-895

Abstract

Legumes have a unique ability to obtain a significant portion of atmospheric nitrogen (N₂) through a symbiotic relationship with Rhizobia spp of bacteria but it takes time, thus, an early supply of N to the plant may positively influence growth and development. However, too much fertilizer in close proximity to the seed can damage the seedling. Therefore, this study was conducted to determine the maximum safe rates for starter seed-row fertilizer application under low seedbed utilization conditions (15%). Emergence, biomass yield and nitrogen (N), phosphorus (P) and sulfur (S) uptake responses to starter fertilizer products and blends applied at 0, 10, 20 and 30?kg?N?ha^?1 in the seed-row were investigated for six different pulse crops: soybean, pea, faba bean, black bean, lentil and chickpea. The general sensitivity (injury potential) for starter N, P, S fertilizer was lentil?≥?pea?≥?chickpea?>?soybean?≥?black bean?>?faba bean. Lentil, pea and chickpea could generally only tolerate the 10?kg?N?ha^?1 rates while soybean and black bean could tolerate 10–20?kg?N?ha^?1. Faba bean emergence appeared relatively unaffected by all three rates of N and showed least sensitivity to seed row placed fertilizer. In terms of 30-day biomass response, soybean and black bean were most responsive to fertilization, while pea, faba bean, lentil and chickpea were least responsive to the starter fertilizer applications, with no benefit increasing above the 10?kg?N?ha^?1 rate.  相似文献   

平板式太阳能供热与制冷联合循环的试验研究     

李明  夏朝凤  尹芳  王六玲  杨为明 《农业工程学报》2003,19(4):269-273

该文提出一种全新的平板式太阳能供热与制冷联合循环新思路，并进行了实物样机制作。将传统太阳能集热器的吸热芯片插入太阳能吸附制冷吸附集热器内的吸附剂中间层，有效地解决太阳能吸附制冷循环过程中吸附床的散热问题，并可有效回收吸附床的显热及吸附热供用户使用。用石英碘钨灯模拟太阳能辐射能量对实物样机进行了试验，结果表明，在接受外界能量16～18 MJ/m²的情况下，集热面积为0.9 m²的平板型太阳能冷热联供装置可对外输出5 kg的冰，并可使热水箱内60 kg的水温升高18℃，系统制冷COP在0.11～0.12之间，总的供热效率在0.45左右。通过试验，证明了所提出的平板式太阳能冷热联供装置结构简单、性能可靠，对太阳能的合理利用作出了一次有效的尝试。  相似文献   

甘蔗茎秆切割力试验   总被引：5，自引：14，他引：5  

刘庆庭  区颖刚  卿上乐  宋春华 《农业工程学报》2007,23(7):90-94

切割力试验是研究甘蔗茎秆切割机理的重要手段。该文在自制的单刀切割试验台上，通过对滑切角、刀盘倾角和切割速度进行三因素三水平正交试验，研究各因素对单位切割力和最大切割力的影响，在此基础上，进行切割速度单因素试验。试验表明：对单位切割力影响的主次顺序为切割速度－滑切角－刀盘倾角；对最大切割力影响的主次顺序为切割速度、刀盘倾角、滑切角。刀盘倾角对最大切割力影响较显著，而对单位切割力影响不显著。进行作物粗茎秆切割力试验时，以单位切割力为试验指标比较合理。单位切割力与切割速度之间呈线性关系，切割速度越大，单位切割力也越大。  相似文献   

Inheritance of Cercospora Leaf Spot Resistance in Mung Bean, Vigna radiata (L.) Wilczek     

S. P. Mishra    A. N. Asthana  Lallan  Yadav 《Plant Breeding》1988,100(3):228-229

Inheritance of Cercospora leaf spot resistance in mungbean was studied in 20 crosses involving crosses of resistant × susceptible, resistant × resistant, susceptible × susceptible lines. 3:1 ratio was observed in all 14 F₂s involving resistant × susceptible parents. The inheritance of Cercospora leaf spot resistance is thus controlled by a single recessive gene. Our results are contradictory to observations of Thaklk et al. (1977 a, b) who found monogenic dominant inheritance of Cercospora leaf spot resistance in mungbean.  相似文献   

Progress of Study in Elasticity Problem with Different Moduli     

HE Xiao-ting  CHEN Shan-lin 《保鲜与加工》2005,(6):136-141

This paper briefly describes elasticity theory with different moduli and research progress in recent twenty years,analyzes computational results respectively from these two theories to all kinds of engineering structures and concludes that applying different moduli theory to solve some engineering components conforms to the real mechanics performance.This paper also deals with the differences between analytical solution and numerical one.Though finite element method is an effective measure to solve these nonlinear problems,seeking analytical solutions is still a difficulty and goal for some problems.  相似文献   

黄河流域棉花品种主要性状时间序列的变化趋势分析   总被引：5，自引：0，他引：5  

王治中  刘秀菊  李伟明  林永增 《棉花学报》2004,16(6):328-332

以棉花黄河区试参试品种的主要性状为原始资料,运用线性回归、谐波及交叉谱分析的原理和技术,对各性状时间序列的线性趋势、周期性变化及相关关系进行了研究。线性回归结果显示,铃重、衣分及霜前花率呈增加趋势,生育期及枯萎病指呈下降趋势。谐波及交叉谱分析结果表明,各序列均存在明显的周期性变化,即皮棉产量、铃重、衣分、生育期及霜前花率以14年为主周期,单株铃数以5.6年为主周期,枯、黄萎病指以28年为主周期;且单株铃数、衣分及霜前花率与皮棉产量在2～3年周期上密切相关,铃重及枯、黄萎病指与皮棉产量在7年周期上密切相关,生育期与皮棉产量在9.3年周期上密切相关。这些结果为育种者掌握育种动态、修正育种目标、提高育种水平及棉花品种主要性状的长期预测提供了科学依据。  相似文献   

水稻主要性状一般配合力间相互关系的初步研究     

郑家奎  何光华  阴国大 《种子》1993,(2)

本文对水稻主要性状一般配合力间的相互关系进行了剖析,结果表明,单株产量一般配合力与结实率;播柚天数和收获指数的一般配合力呈正相关.而与其它性状间的相关不显著.通径分析表明,提高单株产量一般配合力的关键是提高生物产量、每穗粒数和结实率的一般配合力,但不能以增加植株高度和延长生育天数来提高生物产量.讨论提出,提高出叶速度可能是提高生物产量的一条可行途径.  相似文献   

Genome-wide association study identifies genomic loci associated with flight reaction in cattle     

Qiuming Chen  Fengwei Zhang  Kaixing Qu  Quratulain Hanif  Jiafei Shen  Peng Jia  Qingqing Ning  Jingxi Zhan  Jicai Zhang  Ningbo Chen  Hong Chen  Bizhi Huang  Chuzhao Lei 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2020,137(5):477-485

Lower flight reaction is closely related to higher production in cattle, but the genetic basis of lower flight reaction is not clearly understood. Here, we sampled a total of 45 Brahman cattles and 166 Yunling cattles with flight distance (FD), and 73 Brahman cattles and 288 Yunling cattles with crush score (CS) and flight speed (FS), whereas there were 45 Brahman cattles and 161 Yunling cattles with all three traits. The FD, CS and FS in Brahman cattle were significantly lower than those in Yunling cattle. The flight reaction traits had negative correlation with conformational traits (e.g., body weight, withers height and body length). Based on SNPs derived from a subset of 162 whole genomes (25 Brahman genomes and 100 Yunling genomes with FD, 30 Brahman and 131 Yunling genomes with CS and FS), genome-wide association study with mixed linear model was performed to test potential associations between flight reaction traits and genomic variants. We identified five, two and two genomic loci suggestively associated with FD, CS and FS, respectively. Five out of five candidate genes for FD (LOC789753, LRP6, CTIF, SLC9A9 and ZEB1) were reported to be related to Alzheimer's disease representing cognitive impairment in human, which was consistent with the finding that cognitive-behavioural intervention decreased the FD of cows to human. In CS, a very strong association locus was assigned to CDH8, a cadherin involved in synaptic adhesion, axon outgrowth and guidance, whose deletion was associated with autism spectrum disorder. In FS, a very strong association locus was assigned to GABRG2, a gamma-aminobutyric acid (a major inhibitory neurotransmitter in brain) receptor, whose polymorphisms were associated with suicidal behaviour in schizophrenia patients. Our findings will provide targets for molecular-marker selection and genetic manipulation of cattle improvement to meeting the growing demand for lower flight reaction to human.  相似文献